The invention relates to transmission network configuration, especially to an automatically configurable transmission network in the Abis interface of a radio system.
Modern radio networks are highly complicated systems comprising several different network components, such as base stations, base station controllers, mobile services switching centres, different transmission networks and cross-connection devices. When networks extend or the need for capacity increases, building radio networks and extending existing networks becomes a demanding and complex procedure that requires a great deal of planning, time and work.
FIG. 1 illustrates an example of a radio system comprising a base station controller 100, a cross-connection unit 102, three base stations 104 to 108 and a network management system unit 110. The base station 100 is connected by telecommunication connections 112 to the cross-connection unit 102 to which, in turn, the base station 104 is directly connected, and to which the base stations 106 to 108 are coupled in series such that information supplied from the base station controller to the base station 108 is transmitted via the base station 106. By means of existing methods, each element has to be manually configured in situ one network element at a time according to pre-calculated parameters and schemes. Thus, the management connection has to be established manually.
In digital systems information between the network elements is typically transmitted in frames comprising a plurality of time slots. For example in the digital GSM system, a connection between a base station and a base station controller is called an Abis interface. Typically, the connection is a frame connection and comprises 32 time slots transmitting traffic at a 64 kbit/s transmission rate, the total capacity thus being 2 Mbit/s. FIG. 2 illustrates an Abis interface, which consists of 32 time slots (TIME SLOT 0, TIME SLOT 1, TIME SLOT 3 1) each having a capacity of 64 kbit/s. Each connection between a base station and a base station controller takes up some time slots 205 from said frame 210. The number of time slots 205 per base station varies depending on the size of the base station and the capacity of the traffic channel.
When network elements, either cross-connection units or base stations, are to be added to an existing system similar to the system according to FIG. 1, for example, known remote control methods are no longer feasible. When the equipment is physically installed and connected either to an existing or to a built telecommunication connection with the system, the telecommunication connections between a base station and a base station controller must be designed and configured in detail at gate, time slot and partial time slot levels. As far as a network element to be installed is concerned, settings must be fixed by installation personnel in order to enable a management connection to the base station controller to be established, whereupon settings for a new base station can also be fixed from the management unit either manually or by software. Hence, to add a new element is a time-consuming and demanding procedure also susceptible to errors. In order to test a new base station and the telecommunication connections allocated thereto, the base station installation personnel must communicate with the network management personnel. This requires detailed task coordination between the management personnel and the installation personnel so as to avoid unnecessary waiting times.
The methods known in the art disclose that each of the described elements are configured manually on-site, one circuit (transmission connection between the elements) at a time, according to previously calculated parameters and a plan. This configuration work can be automated. Incorporated herein by reference are the PCT Patent Applications PCT/FI99/00351, PCT/FI99/00350 and PCT/FI99/00353, wherein an automatically configurable transmission network is presented. The system described in these patent applications is the preferred operating environment of the current invention, although it is, in principle, suited for any transmission network.
The present invention seeks to provide an improved method of automatically configuring a transmission network. According to an aspect of the present invention, there is provided a method for configuring cross-connections of a radio system as specified in claim 1. According to an aspect of the present invention there is provided a radio system as specified in claim 4.
The preferred embodiments of the invention are disclosed in the dependent claims.
The invention provides several advantages. The amount of necessary manual work decreases significantly. Automation enables potential errors and, consequently, costs to be reduced. Network element installation requires no special and expensive training since automation also reduces the amount of necessary work on the installation site.